s3c2440 spi驱动DMA模式-白红宇

s3c2440 spi驱动DMA模式

阅读量：4052 次

发布时间：2019-05-25

本文共 7204 字，大约阅读时间需要 24 分钟。

#include <linux/irq.h>

#include <linux/miscdevice.h>

#include <linux/delay.h>

#include <asm/irq.h>

#include <linux/interrupt.h>

#include <mach/regs-gpio.h>

#include <mach/hardware.h>

#include <mach/dma.h>

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/init.h>

#include <linux/mm.h>

#include <linux/fs.h>

#include <linux/types.h>

#include <linux/delay.h>

#include <linux/moduleparam.h>

#include <linux/slab.h>

#include <linux/errno.h>

#include <linux/ioctl.h>

#include <linux/cdev.h>

#include <linux/string.h>

#include <linux/gpio.h>

#include <linux/device.h>

#include <linux/uaccess.h>

#include <linux/io.h>

#include <linux/semaphore.h>

#include <asm/uaccess.h>

#include <linux/dma-mapping.h>

#include <asm/atomic.h>

#include <asm/unistd.h>

#include <linux/spinlock.h>

#include <linux/clk.h>

#include <asm/system.h>

#include <asm/signal.h>

#include <asm/io.h>

#include <asm/dma.h>

#define DEVICE_NAME "tq2440_spi"

#define DBG(msg...) do{ \

if(debug)\

printk(KERN_INFO msg);\

}while(0)

static int debug=1;

static int spi_major=0;

module_param(spi_major,int,S_IRUGO);

static struct class *spi_class;

static struct semaphore sem;

struct cdev spiCdev;

static int spi_open(struct inode *,struct file *);

static int spi_release(struct inode *,struct file *);

static ssize_t spi_write(struct file *filp,const char *buf,size_t count,loff_t *f_ops);

static ssize_t spi_read(struct file *filp,char *buf,size_t count,loff_t *f_ops);

static ssize_t spi_ioctl(struct inode *inode,struct file *filp,unsigned int cmd,unsigned long data);

static void config_write(void);

static void config_read(void);

typedef struct {

int size;

char *start;

dma_addr_t dma_addr;

struct semaphore sem;

}spi_buff_t;

static spi_buff_t output_buff;

static spi_buff_t input_buff;

volatile unsigned long *s3c2440_clkcon;

volatile unsigned long *spi_spcon1;//SPI Part define

volatile unsigned long *spi_spsta1;

volatile unsigned long *spi_sppin1;

volatile unsigned long *spi_sppre1;

volatile unsigned long *spi_sptdat1;

volatile unsigned long *spi_sprdat1;

static struct s3c2410_dma_client spi_dma_client={

.name="SPI",

};

static const struct file_operations spi_fops =

{

.owner=THIS_MODULE,

.open=spi_open,

.read=spi_read,

.ioctl=spi_ioctl,

.release=spi_release,

.write=spi_write,

};

static void spi_clear_buf(spi_buff_t *s)

{

DBG("spi_clear_buf\n");

s3c2410_dma_ctrl(DMACH_SPI1,S3C2410_DMAOP_FLUSH);

dma_free_coherent(NULL,s->size,s->start,s->dma_addr);

}

static int spi_open(struct inode *inode,struct file *filp)

{

DBG("spi_open\n");

if(down_interruptible(&sem))

return -ERESTARTSYS;

filp->private_data =&spiCdev;

return 0;

}

static int spi_release(struct inode *inode,struct file *filp)

{

up(&sem);

DBG("release\n");

return 0;

}

static int spi_setup_buf(spi_buff_t *s)

{

char *dmabuf=0;

dma_addr_t dmaphys=0;

int dmasize=s->size;

DBG("spi_setup_buf\n");

dmabuf=dma_alloc_coherent(NULL,dmasize,&dmaphys,GFP_KERNEL|GFP_DMA);

if(!dmabuf)

goto err;

s->start=dmabuf;

s->dma_addr=dmaphys;

init_MUTEX(&s->sem);

DBG("buf start %p dma %d\n",s->start,s->dma_addr);

return 0;

err:

printk(KERN_ERR "unable to allocate spi menmory\n");

return -ENOMEM;

}

static ssize_t spi_read(struct file *filp,char __user *buf,size_t count,loff_t *f_ops)

{

spi_buff_t *s=&input_buff;

DBG("spi read!\n");

config_read();

s->size=count;

if(spi_setup_buf(s))

return -ENOMEM;

down(&s->sem);

s3c2410_dma_enqueue(DMACH_SPI1,(void *)s,s->dma_addr,s->size);

if(copy_to_user(buf,s->start,s->size)){

printk("copy_to_user error\n");

up(&s->sem);

}

return s->size;

}

static ssize_t spi_write(struct file *filp,const char __user *buf,size_t count,loff_t *f_ops)

{

int ret=0;

spi_buff_t *s=&output_buff;

DBG("spi_write:start count=%d\n",count);

config_write();

s->size=count;

if(spi_setup_buf(s)){

printk("err no mem\n");

return -ENOMEM;

}

if(down_interruptible(&s->sem)){

printk("down interruptible error\n");

}

if(copy_from_user(s->start,buf,count)){

printk("copy_from_user error\n");

up(&s->sem);

return -EFAULT;

}

if((ret=s3c2410_dma_enqueue(DMACH_SPI1,(void*)s,s->dma_addr,s->size))){

printk("dma enqueue failed.\n");

return ret;

}

return count;

}

static ssize_t spi_ioctl(struct inode *inode,struct file *filp,unsigned int cmd,unsigned long data)

{

return 0;

}

static void spi_dmain_done_callback(struct s3c2410_dma_chan *ch,void *buf,int size,

enum s3c2410_dma_buffresult result)

{

spi_buff_t *b=(spi_buff_t *)buf;

DBG("spi_dmain_done_callback\n");

b->size=size;

up(&b->sem);

}

static void spi_dmaout_done_callback(struct s3c2410_dma_chan *ch,void *buf,int size,

enum s3c2410_dma_buffresult result)

{

spi_buff_t *b=(spi_buff_t *)buf;

DBG("spi_dmaout_done_callback\n");

up(&b->sem);

}

static void config_write(void)

{

enum s3c2410_dmasrc source;

int hwcfg;

unsigned long devaddr;

int dcon;

unsigned int flags=0;

DBG("spi config_dma\n");

source=S3C2410_DMASRC_MEM;

hwcfg=3;

devaddr=0x59000030;

dcon=0X2a800000;

flags=S3C2410_DMAF_AUTOSTART;

s3c2410_dma_devconfig(DMACH_SPI1, source, hwcfg, devaddr);

s3c2410_dma_config(DMACH_SPI1, 1, dcon);

s3c2410_dma_set_buffdone_fn(DMACH_SPI1, spi_dmaout_done_callback);

s3c2410_dma_setflags(DMACH_SPI1, flags);

}

static void config_read(void)

{

enum s3c2410_dmasrc source;

int hwcfg;

unsigned long devaddr;

int dcon;

unsigned int flags=0;

DBG("spi config_read\n");

source=S3C2410_DMASRC_HW;

hwcfg=3;

devaddr=0x59000034;

dcon=0X2a800000;

flags=S3C2410_DMAF_AUTOSTART;

s3c2410_dma_devconfig(DMACH_SPI1, source, hwcfg, devaddr);

s3c2410_dma_config(DMACH_SPI1, 1, dcon);

s3c2410_dma_set_buffdone_fn(DMACH_SPI1, spi_dmain_done_callback);

s3c2410_dma_setflags(DMACH_SPI1, flags);

}

static int spi_init_dma(spi_buff_t *s,char *desc)

{

int ret;

DBG("spi init dma\n");

ret=!s3c2410_dma_request(DMACH_SPI1,&spi_dma_client,NULL);

if(ret){

spi_clear_buf(s);

printk(KERN_ERR "failed to get dma channel\n");

}

return ret;

}

static int spi_clear_dma(spi_buff_t *s,struct s3c2410_dma_client *client)

{

DBG("spi_clear_dma\n");

s3c2410_dma_set_buffdone_fn(DMACH_SPI1,NULL);

s3c2410_dma_free(DMACH_SPI1,client);

return 0;

}

static void config_spi(void)

{

s3c2410_gpio_cfgpin(S3C2410_GPG5,S3C2410_GPG5_SPIMISO1);

s3c2410_gpio_cfgpin(S3C2410_GPG6,S3C2410_GPG6_SPIMOSI1);

s3c2410_gpio_cfgpin(S3C2410_GPG7,S3C2410_GPG7_SPICLK1);

s3c2410_gpio_cfgpin(S3C2410_GPG3,S3C2410_GPG3_nSS1);

s3c2410_gpio_pullup(S3C2410_GPG5,1);

s3c2410_gpio_pullup(S3C2410_GPG6,1);

s3c2410_gpio_pullup(S3C2410_GPG7,1);

*s3c2440_clkcon |=0x40000;

ioremap_spi();

config_spi();

if(spi_init_dma(&output_buff,"spi out")){

spi_clear_dma(&output_buff,&spi_dma_client);

printk(KERN_ERR "SPI_OUT"":unable to get DMA channel\n");

return -EBUSY;

}

spi_class=class_create(THIS_MODULE,DEVICE_NAME);

if(IS_ERR(spi_class))

{

printk("Err:failed in spi class.\n");

return -1;

}

device_create(spi_class,NULL,devno,NULL,DEVICE_NAME);

printk("Init spi success!\n");

return result;

}

static void __exit spi_exit(void)

{

cdev_del(&spiCdev);

unregister_chrdev_region(MKDEV(spi_major, 0), 1);

device_destroy(spi_class ,MKDEV(spi_major,0));

class_destroy(spi_class);

spi_clear_dma(&output_buff,&spi_dma_client);

iounmap_spi();

printk("spi_exit!\n");

}

module_init(spi_init);

module_exit(spi_exit);

MODULE_LICENSE("GPL");

MODULE_AUTHOR("syw");

MODULE_DESCRIPTION("SPI driver for S3C2440");

转载地址：http://wipci.baihongyu.com/

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